/*
 * Copyright 2017 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *       http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.example.camera2demo.camera2basic;


import android.Manifest;
import android.app.Activity;
import android.app.AlertDialog;
import android.app.Dialog;
import android.content.Context;
import android.content.DialogInterface;
import android.content.pm.PackageManager;
import android.content.res.Configuration;
import android.graphics.ImageFormat;
import android.graphics.Matrix;
import android.graphics.Point;
import android.graphics.RectF;
import android.graphics.SurfaceTexture;
import android.hardware.camera2.CameraAccessException;
import android.hardware.camera2.CameraCaptureSession;
import android.hardware.camera2.CameraCharacteristics;
import android.hardware.camera2.CameraDevice;
import android.hardware.camera2.CameraManager;
import android.hardware.camera2.CameraMetadata;
import android.hardware.camera2.CaptureRequest;
import android.hardware.camera2.CaptureResult;
import android.hardware.camera2.TotalCaptureResult;
import android.hardware.camera2.params.StreamConfigurationMap;
import android.media.Image;
import android.media.ImageReader;
import android.os.Bundle;
import android.os.Environment;
import android.os.Handler;
import android.os.HandlerThread;
import android.text.TextUtils;
import android.util.DisplayMetrics;
import android.util.Log;
import android.util.Size;
import android.util.SparseIntArray;
import android.view.LayoutInflater;
import android.view.Surface;
import android.view.TextureView;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Toast;

import com.example.camera2demo.R;

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.nio.ByteBuffer;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.Comparator;
import java.util.List;
import java.util.concurrent.Semaphore;
import java.util.concurrent.TimeUnit;

import androidx.annotation.NonNull;
import androidx.core.app.ActivityCompat;
import androidx.core.content.ContextCompat;
import androidx.fragment.app.DialogFragment;
import androidx.fragment.app.Fragment;


/**
 * Camera2 中主要的API类
 * <p>
 * CameraManager类 : 摄像头管理类，用于检测、打开系统摄像头，通过getCameraCharacteristics(cameraId)可以获取摄像头特征。
 * <p>
 * CameraCharacteristics类：相机特性类，例如，是否支持自动调焦，是否支持zoom，是否支持闪光灯一系列特征。
 * <p>
 * CameraDevice类： 相机设备,类似早期的camera类。
 * <p>
 * CameraCaptureSession类：用于创建预览、拍照的Session类。通过它的setRepeatingRequest()方法控制预览界面 , 通过它的capture()方法控制拍照动作或者录像动作。
 * <p>
 * CameraRequest类：一次捕获的请求，可以设置一些列的参数，用于控制预览和拍照参数，例如：对焦模式，曝光模式，zoom参数等等。
 * <p>
 * ————————————————
 * 原文链接：https://blog.csdn.net/hexingen/article/details/79290046
 */
public class Camera2BasicFragment extends Fragment
        implements View.OnClickListener, ActivityCompat.OnRequestPermissionsResultCallback {

    /**
     * Conversion from screen rotation to JPEG orientation.
     */
    private static final SparseIntArray ORIENTATIONS = new SparseIntArray();
    private static final int REQUEST_CAMERA_PERMISSION = 1;
    private static final String FRAGMENT_DIALOG = "dialog";

    static {
        ORIENTATIONS.append(Surface.ROTATION_0, 90);
        ORIENTATIONS.append(Surface.ROTATION_90, 0);
        ORIENTATIONS.append(Surface.ROTATION_180, 270);
        ORIENTATIONS.append(Surface.ROTATION_270, 180);
    }

    /**
     * Tag for the {@link Log}.
     */
    private static final String TAG = "Camera2BasicFragment";

    /**
     * Camera state: Showing camera preview.
     */
    private static final int STATE_PREVIEW = 0;

    /**
     * Camera state: Waiting for the focus to be locked.
     */
    private static final int STATE_WAITING_LOCK = 1;

    /**
     * Camera state: Waiting for the exposure to be precapture state.
     */
    private static final int STATE_WAITING_PRECAPTURE = 2;

    /**
     * Camera state: Waiting for the exposure state to be something other than precapture.
     */
    private static final int STATE_WAITING_NON_PRECAPTURE = 3;

    /**
     * Camera state: Picture was taken.
     */
    private static final int STATE_PICTURE_TAKEN = 4;

    /**
     * Max preview width that is guaranteed by Camera2 API
     */
    private static final int MAX_PREVIEW_WIDTH = 1920;

    /**
     * Max preview height that is guaranteed by Camera2 API
     */
    private static final int MAX_PREVIEW_HEIGHT = 1080;

    /**
     * {@link TextureView.SurfaceTextureListener} handles several lifecycle events on a
     * {@link TextureView}.
     */
    private final TextureView.SurfaceTextureListener mSurfaceTextureListener = new TextureView.SurfaceTextureListener() {

        @Override
        public void onSurfaceTextureAvailable(SurfaceTexture texture, int width, int height) {
            //当SurefaceTexture可用的时候，设置相机参数并打开相机
//            setUpCameraOutputs(width, height);
            openCamera(width, height);
        }

        @Override
        public void onSurfaceTextureSizeChanged(SurfaceTexture texture, int width, int height) {
            configureTransform(width, height);
        }

        @Override
        public boolean onSurfaceTextureDestroyed(SurfaceTexture texture) {
            return true;
        }

        @Override
        public void onSurfaceTextureUpdated(SurfaceTexture texture) {
        }

    };

    /**
     * ID of the current {@link CameraDevice}.
     */
    private String mCameraId;

    /**
     * An {@link AutoFitTextureView} for camera preview.
     */
    private AutoFitTextureView mTextureView;

    /**
     * A {@link CameraCaptureSession } for camera preview.
     */
    private CameraCaptureSession mCaptureSession;

    /**
     * A reference to the opened {@link CameraDevice}.
     */
    private CameraDevice mCameraDevice;

    /**
     * The {@link Size} of camera preview.
     */
    private Size mPreviewSize;

    /**
     * {@link CameraDevice.StateCallback} is called when {@link CameraDevice} changes its state.
     * 摄像头状态回调
     */
    private final CameraDevice.StateCallback mStateCallback = new CameraDevice.StateCallback() {

        @Override
        public void onOpened(@NonNull CameraDevice cameraDevice) {
            //相机打开，得到CameraDevice对象
            // This method is called when the camera is opened.  We start camera preview here.
            mCameraOpenCloseLock.release();
            mCameraDevice = cameraDevice;
            createCameraPreviewSession();
        }

        @Override
        public void onDisconnected(@NonNull CameraDevice cameraDevice) {
            //相机断开连接
            mCameraOpenCloseLock.release();
            cameraDevice.close();
            mCameraDevice = null;
        }

        @Override
        public void onError(@NonNull CameraDevice cameraDevice, int error) {
            //相机错误
            mCameraOpenCloseLock.release();
            cameraDevice.close();
            mCameraDevice = null;
            Activity activity = getActivity();
            if (null != activity) {
                activity.finish();
            }
        }

    };

    /**
     * An additional thread for running tasks that shouldn't block the UI.
     */
    private HandlerThread mBackgroundThread;

    /**
     * A {@link Handler} for running tasks in the background.
     */
    private Handler mBackgroundHandler;

    /**
     * An {@link ImageReader} that handles still image capture.
     */
    private ImageReader mImageReader;

    /**
     * This is the output file for our picture.
     */
    private File mFile;

    /**
     * This a callback object for the {@link ImageReader}. "onImageAvailable" will be called when a
     * still image is ready to be saved.
     * （静态图片是否已准备好监听）
     */
    private final ImageReader.OnImageAvailableListener mOnImageAvailableListener = new ImageReader.OnImageAvailableListener() {

        @Override
        public void onImageAvailable(ImageReader reader) {
            //设置拍照图片保存路径
            mBackgroundHandler.post(new ImageSaver(reader.acquireNextImage(), mFile));

            //获取帧数据
            Image image = reader.acquireLatestImage();
            //处理逻辑
            if (image != null) {
                ByteBuffer buffer = image.getPlanes()[0].getBuffer();
                byte[] data = new byte[buffer.remaining()];
                Log.d(TAG, "data-size=" + data.length);
                buffer.get(data);
                image.close();
            }
        }
    };

    /**
     * {@link CaptureRequest.Builder} for the camera preview
     */
    private CaptureRequest.Builder mPreviewRequestBuilder;

    /**
     * {@link CaptureRequest} generated by {@link #mPreviewRequestBuilder}
     */
    private CaptureRequest mPreviewRequest;

    /**
     * The current state of camera state for taking pictures.
     *
     * @see #mCaptureCallback
     */
    private int mState = STATE_PREVIEW;

    /**
     * A {@link Semaphore} to prevent the app from exiting before closing the camera.
     */
    private Semaphore mCameraOpenCloseLock = new Semaphore(1);

    /**
     * Whether the current camera device supports Flash or not.
     */
    private boolean mFlashSupported;

    /**
     * Orientation of the camera sensor
     */
    private int mSensorOrientation;

    /**
     * A {@link CameraCaptureSession.CaptureCallback} that handles events related to JPEG capture.
     * JPEG数据捕获回调
     */
    private CameraCaptureSession.CaptureCallback mCaptureCallback = new CameraCaptureSession.CaptureCallback() {

        private void process(CaptureResult result) {
            switch (mState) {
                case STATE_PREVIEW: {
                    // We have nothing to do when the camera preview is working normally.(预览正常时)
                    break;
                }
                case STATE_WAITING_LOCK: {
                    Integer afState = result.get(CaptureResult.CONTROL_AF_STATE);
                    if (afState == null) {
                        captureStillPicture();
                    } else if (CaptureResult.CONTROL_AF_STATE_FOCUSED_LOCKED == afState ||
                            CaptureResult.CONTROL_AF_STATE_NOT_FOCUSED_LOCKED == afState) {
                        // CONTROL_AE_STATE can be null on some devices
                        Integer aeState = result.get(CaptureResult.CONTROL_AE_STATE);
                        if (aeState == null || aeState == CaptureResult.CONTROL_AE_STATE_CONVERGED) {
                            mState = STATE_PICTURE_TAKEN;
                            captureStillPicture();
                        } else {
                            runPrecaptureSequence();
                        }
                    }
                    break;
                }
                case STATE_WAITING_PRECAPTURE: {
                    // CONTROL_AE_STATE can be null on some devices
                    Integer aeState = result.get(CaptureResult.CONTROL_AE_STATE);
                    if (aeState == null ||
                            aeState == CaptureResult.CONTROL_AE_STATE_PRECAPTURE ||
                            aeState == CaptureRequest.CONTROL_AE_STATE_FLASH_REQUIRED) {
                        mState = STATE_WAITING_NON_PRECAPTURE;
                    }
                    break;
                }
                case STATE_WAITING_NON_PRECAPTURE: {
                    // CONTROL_AE_STATE can be null on some devices
                    Integer aeState = result.get(CaptureResult.CONTROL_AE_STATE);
                    if (aeState == null || aeState != CaptureResult.CONTROL_AE_STATE_PRECAPTURE) {
                        mState = STATE_PICTURE_TAKEN;
                        captureStillPicture();
                    }
                    break;
                }
            }
        }

        @Override
        public void onCaptureProgressed(@NonNull CameraCaptureSession session,
                                        @NonNull CaptureRequest request,
                                        @NonNull CaptureResult partialResult) {
            process(partialResult);
        }

        @Override
        public void onCaptureCompleted(@NonNull CameraCaptureSession session,
                                       @NonNull CaptureRequest request,
                                       @NonNull TotalCaptureResult result) {
            process(result);
        }

    };
    private String mChangedCameraId = null;

    /**
     * Shows a {@link Toast} on the UI thread.
     *
     * @param text The message to show
     */
    private void showToast(final String text) {
        final Activity activity = getActivity();
        if (activity != null) {
            activity.runOnUiThread(new Runnable() {
                @Override
                public void run() {
                    Toast.makeText(activity, text, Toast.LENGTH_SHORT).show();
                }
            });
        }
    }

    /**
     * Given {@code choices} of {@code Size}s supported by a camera, choose the smallest one that
     * is at least as large as the respective texture view size, and that is at most as large as the
     * respective max size, and whose aspect ratio matches with the specified value. If such size
     * doesn't exist, choose the largest one that is at most as large as the respective max size,
     * and whose aspect ratio matches with the specified value.
     *
     * @param choices           The list of sizes that the camera supports for the intended output
     *                          class
     * @param textureViewWidth  The width of the texture view relative to sensor coordinate
     * @param textureViewHeight The height of the texture view relative to sensor coordinate
     * @param maxWidth          The maximum width that can be chosen
     * @param maxHeight         The maximum height that can be chosen
     * @param aspectRatio       The aspect ratio
     * @return The optimal {@code Size}, or an arbitrary one if none were big enough
     */
    private static Size chooseOptimalSize(Size[] choices, int textureViewWidth,
                                          int textureViewHeight, int maxWidth, int maxHeight, Size aspectRatio) {

        // Collect the supported resolutions that are at least as big as the preview Surface
        List<Size> bigEnough = new ArrayList<>();
        // Collect the supported resolutions that are smaller than the preview Surface
        List<Size> notBigEnough = new ArrayList<>();
        int w = aspectRatio.getWidth();
        int h = aspectRatio.getHeight();
        for (Size option : choices) {
            if (option.getWidth() <= maxWidth && option.getHeight() <= maxHeight &&
                    option.getHeight() == option.getWidth() * h / w) {
                if (option.getWidth() >= textureViewWidth &&
                        option.getHeight() >= textureViewHeight) {
                    bigEnough.add(option);
                } else {
                    notBigEnough.add(option);
                }
            }
        }

        // Pick the smallest of those big enough. If there is no one big enough, pick the
        // largest of those not big enough.
        if (bigEnough.size() > 0) {
            return Collections.min(bigEnough, new CompareSizesByArea());
        } else if (notBigEnough.size() > 0) {
            return Collections.max(notBigEnough, new CompareSizesByArea());
        } else {
            Log.e(TAG, "Couldn't find any suitable preview size");
            return choices[0];
        }
    }

    public static Camera2BasicFragment newInstance() {
        return new Camera2BasicFragment();
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        return inflater.inflate(R.layout.fragment_camera2_basic, container, false);
    }

    @Override
    public void onViewCreated(final View view, Bundle savedInstanceState) {
        view.findViewById(R.id.picture).setOnClickListener(this);
        view.findViewById(R.id.info).setOnClickListener(this);
        view.findViewById(R.id.switch_camera).setOnClickListener(this);
        mTextureView = (AutoFitTextureView) view.findViewById(R.id.texture);
    }

    @Override
    public void onActivityCreated(Bundle savedInstanceState) {
        super.onActivityCreated(savedInstanceState);
        mFile = new File(Environment.getExternalStorageDirectory()
                + "/DCIM/Camera/aaa.jpg");
    }

    @Override
    public void onResume() {
        super.onResume();
        startBackgroundThread();

        // When the screen is turned off and turned back on, the SurfaceTexture is already
        // available, and "onSurfaceTextureAvailable" will not be called. In that case, we can open
        // a camera and start preview from here (otherwise, we wait until the surface is ready in
        // the SurfaceTextureListener).
        //关闭屏幕然后再打开时，SurfaceTexture已经存在
        //可用，并且不会调用“ onSurfaceTextureAvailable”。 在这种情况下，我们可以打开
        //摄像头，然后从此处开始预览（否则，我们将通过SurfaceTextureListener的onSurfaceTextureAvailable打开相机
        if (mTextureView.isAvailable()) {
            openCamera(mTextureView.getWidth(), mTextureView.getHeight());
        } else {
            mTextureView.setSurfaceTextureListener(mSurfaceTextureListener);
        }
    }

    @Override
    public void onPause() {
        closeCamera();
        stopBackgroundThread();
        super.onPause();
    }

    private void requestCameraPermission() {
        if (shouldShowRequestPermissionRationale(Manifest.permission.CAMERA)) {
            new ConfirmationDialog().show(getChildFragmentManager(), FRAGMENT_DIALOG);
        } else {
            requestPermissions(new String[]{Manifest.permission.CAMERA}, REQUEST_CAMERA_PERMISSION);
        }
    }

    @Override
    public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions,
                                           @NonNull int[] grantResults) {
        if (requestCode == REQUEST_CAMERA_PERMISSION) {
            if (grantResults.length != 1 || grantResults[0] != PackageManager.PERMISSION_GRANTED) {
                ErrorDialog.newInstance(getString(R.string.request_permission))
                        .show(getChildFragmentManager(), FRAGMENT_DIALOG);
            }
        } else {
            super.onRequestPermissionsResult(requestCode, permissions, grantResults);
        }
    }

    /**
     * Sets up member variables related to camera.
     * （设置与相机相关的成员变量）
     *
     * @param width  The width of available size for camera preview（可用的预览尺寸宽度）
     * @param height The height of available size for camera preview（可用的预览尺寸高度）
     */
    @SuppressWarnings("SuspiciousNameCombination")
    private void setUpCameraOutputs(int width, int height) {
        Activity activity = getActivity();
        CameraManager manager = (CameraManager) activity.getSystemService(Context.CAMERA_SERVICE);
        try {
            //getCameraIdList（） 获取摄像头id列表
            for (String cameraId : manager.getCameraIdList()) {
                //获取摄像头特征
                CameraCharacteristics characteristics = manager.getCameraCharacteristics(cameraId);

                // We don't use a front facing camera in this sample.（获取摄像头朝向，前置还是后置）
                Integer facing = characteristics.get(CameraCharacteristics.LENS_FACING);
                Log.i(TAG, "摄像头facing: " + facing + " ,cameraId:" + cameraId);
                //facing的值与cameraId是相反的，facing：前0后1，cameraId：前1后0
                if (facing != null && facing == CameraCharacteristics.LENS_FACING_FRONT) {
                    //本demo不使用前置摄像头，跳过循环
                    continue;
                }

                StreamConfigurationMap map = characteristics.get(CameraCharacteristics.SCALER_STREAM_CONFIGURATION_MAP);
                if (map == null) {
                    continue;
                }

                // For still image captures, we use the largest available size.
                Size largest = Collections.max(
                        Arrays.asList(map.getOutputSizes(ImageFormat.JPEG)),
                        new CompareSizesByArea());
                mImageReader = ImageReader.newInstance(1280, 720,
                        ImageFormat.JPEG, /*maxImages*/2);
                mImageReader.setOnImageAvailableListener(
                        mOnImageAvailableListener, mBackgroundHandler);

                // Find out if we need to swap dimension to get the preview size relative to sensor
                // coordinate.
                int displayRotation = activity.getWindowManager().getDefaultDisplay().getRotation();
                //noinspection ConstantConditions
                mSensorOrientation = characteristics.get(CameraCharacteristics.SENSOR_ORIENTATION);
                boolean swappedDimensions = false;
                switch (displayRotation) {
                    case Surface.ROTATION_0:
                    case Surface.ROTATION_180:
                        if (mSensorOrientation == 90 || mSensorOrientation == 270) {
                            swappedDimensions = true;
                        }
                        break;
                    case Surface.ROTATION_90:
                    case Surface.ROTATION_270:
                        if (mSensorOrientation == 0 || mSensorOrientation == 180) {
                            swappedDimensions = true;
                        }
                        break;
                    default:
                        Log.e(TAG, "Display rotation is invalid: " + displayRotation);
                }

                Point displaySize = new Point();
                activity.getWindowManager().getDefaultDisplay().getSize(displaySize);
                int rotatedPreviewWidth = width;
                int rotatedPreviewHeight = height;
                int maxPreviewWidth = displaySize.x;
                int maxPreviewHeight = displaySize.y;

                if (swappedDimensions) {
                    rotatedPreviewWidth = height;
                    rotatedPreviewHeight = width;
                    maxPreviewWidth = displaySize.y;
                    maxPreviewHeight = displaySize.x;
                }

                if (maxPreviewWidth > MAX_PREVIEW_WIDTH) {
                    maxPreviewWidth = MAX_PREVIEW_WIDTH;
                }

                if (maxPreviewHeight > MAX_PREVIEW_HEIGHT) {
                    maxPreviewHeight = MAX_PREVIEW_HEIGHT;
                }

                // Danger, W.R.! Attempting to use too large a preview size could  exceed the camera
                // bus' bandwidth limitation, resulting in gorgeous previews but the storage of
                // garbage capture data.
                mPreviewSize = chooseOptimalSize(map.getOutputSizes(SurfaceTexture.class),
                        rotatedPreviewWidth, rotatedPreviewHeight, maxPreviewWidth,
                        maxPreviewHeight, largest);

                // We fit the aspect ratio of TextureView to the size of preview we picked.
                int orientation = getResources().getConfiguration().orientation;
                if (orientation == Configuration.ORIENTATION_LANDSCAPE) {
                    mTextureView.setAspectRatio(mPreviewSize.getWidth(), mPreviewSize.getHeight());
                } else {
                    mTextureView.setAspectRatio(mPreviewSize.getHeight(), mPreviewSize.getWidth());
                }

                // Check if the flash is supported.（是否支持闪光灯）
                Boolean available = characteristics.get(CameraCharacteristics.FLASH_INFO_AVAILABLE);
                mFlashSupported = available == null ? false : available;

                mCameraId = cameraId;
                return;
            }
        } catch (CameraAccessException e) {
            e.printStackTrace();
        } catch (NullPointerException e) {
            // Currently an NPE is thrown when the Camera2API is used but not supported on the
            // device this code runs.
            ErrorDialog.newInstance(getString(R.string.camera_error))
                    .show(getChildFragmentManager(), FRAGMENT_DIALOG);
        }
    }

    /**
     * 打开相机 {@link Camera2BasicFragment#mCameraId}.
     */
    private void openCamera(int width, int height) {
        if (ContextCompat.checkSelfPermission(getActivity(), Manifest.permission.CAMERA)
                != PackageManager.PERMISSION_GRANTED) {
            requestCameraPermission();
            return;
        }
        getMatchingSize2();
        setUpCameraOutputs(width, height);
        configureTransform(width, height);
        Activity activity = getActivity();
        CameraManager manager = (CameraManager) activity.getSystemService(Context.CAMERA_SERVICE);
        try {
            if (!mCameraOpenCloseLock.tryAcquire(2500, TimeUnit.MILLISECONDS)) {
                throw new RuntimeException("Time out waiting to lock camera opening.");
            }
            manager.openCamera(mChangedCameraId == null ? mCameraId : mChangedCameraId, mStateCallback, mBackgroundHandler);
        } catch (CameraAccessException e) {
            e.printStackTrace();
        } catch (InterruptedException e) {
            throw new RuntimeException("Interrupted while trying to lock camera opening.", e);
        }
    }

    /**
     * 关闭相机
     */
    private void closeCamera() {
        try {
            mCameraOpenCloseLock.acquire();
            if (null != mCaptureSession) {
                mCaptureSession.close();
                mCaptureSession = null;
            }
            if (null != mCameraDevice) {
                mCameraDevice.close();
                mCameraDevice = null;
            }
            if (null != mImageReader) {
                mImageReader.close();
                mImageReader = null;
            }
        } catch (InterruptedException e) {
            throw new RuntimeException("Interrupted while trying to lock camera closing.", e);
        } finally {
            mCameraOpenCloseLock.release();
        }
    }

    /**
     * Starts a background thread and its {@link Handler}.
     * （开启后台线程和绑定的Handler）
     */
    private void startBackgroundThread() {
        mBackgroundThread = new HandlerThread("CameraBackground");
        mBackgroundThread.start();
        mBackgroundHandler = new Handler(mBackgroundThread.getLooper());
    }

    /**
     * Stops the background thread and its {@link Handler}.
     */
    private void stopBackgroundThread() {
        mBackgroundThread.quitSafely();
        try {
            mBackgroundThread.join();
            mBackgroundThread = null;
            mBackgroundHandler = null;
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
    }

    /**
     * Creates a new {@link CameraCaptureSession} for camera preview.
     */
    private void createCameraPreviewSession() {
        try {
            SurfaceTexture texture = mTextureView.getSurfaceTexture();
            assert texture != null;

            // We configure the size of default buffer to be the size of camera preview we want.
            texture.setDefaultBufferSize(mPreviewSize.getWidth(), mPreviewSize.getHeight());

            // This is the output Surface we need to start preview.
            Surface surface = new Surface(texture);

            // We set up a CaptureRequest.Builder with the output Surface.
            mPreviewRequestBuilder = mCameraDevice.createCaptureRequest(CameraDevice.TEMPLATE_PREVIEW);
            mPreviewRequestBuilder.addTarget(surface);

            // Here, we create a CameraCaptureSession for camera preview.
            mCameraDevice.createCaptureSession(Arrays.asList(surface, mImageReader.getSurface()), new CameraCaptureSession.StateCallback() {

                @Override
                public void onConfigured(@NonNull CameraCaptureSession cameraCaptureSession) {
                    // The camera is already closed
                    if (null == mCameraDevice) {
                        return;
                    }

                    // When the session is ready, we start displaying the preview.
                    mCaptureSession = cameraCaptureSession;
                    try {
                        //自动对焦
                        mPreviewRequestBuilder.set(CaptureRequest.CONTROL_AF_MODE,
                                CaptureRequest.CONTROL_AF_MODE_CONTINUOUS_PICTURE);
                        //自动开启闪光灯
                        setAutoFlash(mPreviewRequestBuilder);

                        // Finally, we start displaying the camera preview.
                        mPreviewRequest = mPreviewRequestBuilder.build();
                        mCaptureSession.setRepeatingRequest(mPreviewRequest,
                                mCaptureCallback, mBackgroundHandler);
                    } catch (CameraAccessException e) {
                        e.printStackTrace();
                    }
                }

                @Override
                public void onConfigureFailed(@NonNull CameraCaptureSession cameraCaptureSession) {
                    showToast("Failed");
                }
            }, null);
        } catch (CameraAccessException e) {
            e.printStackTrace();
        }
    }

    /**
     * Configures the necessary {@link Matrix} transformation to `mTextureView`.
     * This method should be called after the camera preview size is determined in
     * setUpCameraOutputs and also the size of `mTextureView` is fixed.
     *
     * @param viewWidth  The width of `mTextureView`
     * @param viewHeight The height of `mTextureView`
     */
    private void configureTransform(int viewWidth, int viewHeight) {
        Activity activity = getActivity();
        if (null == mTextureView || null == mPreviewSize || null == activity) {
            return;
        }
        int rotation = activity.getWindowManager().getDefaultDisplay().getRotation();
        Matrix matrix = new Matrix();
        RectF viewRect = new RectF(0, 0, viewWidth, viewHeight);
        RectF bufferRect = new RectF(0, 0, mPreviewSize.getHeight(), mPreviewSize.getWidth());
        float centerX = viewRect.centerX();
        float centerY = viewRect.centerY();
        Log.i(TAG, "configureTransform: ------rotation------" + rotation);
        if (Surface.ROTATION_90 == rotation || Surface.ROTATION_270 == rotation) {
            bufferRect.offset(centerX - bufferRect.centerX(), centerY - bufferRect.centerY());
            matrix.setRectToRect(viewRect, bufferRect, Matrix.ScaleToFit.FILL);
            float scale = Math.max(
                    (float) viewHeight / mPreviewSize.getHeight(),
                    (float) viewWidth / mPreviewSize.getWidth());
            matrix.postScale(scale, scale, centerX, centerY);
            matrix.postRotate(90 * (rotation - 2), centerX, centerY);
        } else if (Surface.ROTATION_180 == rotation) {
            matrix.postRotate(180, centerX, centerY);
        }
        mTextureView.setTransform(matrix);
    }

    /**
     * Initiate a still image capture.
     */
    private void takePicture() {
        lockFocus();
    }

    /**
     * Lock the focus as the first step for a still image capture.
     */
    private void lockFocus() {
        try {
            // This is how to tell the camera to lock focus.
            mPreviewRequestBuilder.set(CaptureRequest.CONTROL_AF_TRIGGER, CameraMetadata.CONTROL_AF_TRIGGER_START);
            // Tell #mCaptureCallback to wait for the lock.
            mState = STATE_WAITING_LOCK;
            mCaptureSession.capture(mPreviewRequestBuilder.build(), mCaptureCallback, mBackgroundHandler);
        } catch (CameraAccessException e) {
            e.printStackTrace();
        }
    }

    /**
     * Run the precapture sequence for capturing a still image. This method should be called when
     * we get a response in {@link #mCaptureCallback} from {@link #lockFocus()}.
     */
    private void runPrecaptureSequence() {
        try {
            // This is how to tell the camera to trigger.
            mPreviewRequestBuilder.set(CaptureRequest.CONTROL_AE_PRECAPTURE_TRIGGER,
                    CaptureRequest.CONTROL_AE_PRECAPTURE_TRIGGER_START);
            // Tell #mCaptureCallback to wait for the precapture sequence to be set.
            mState = STATE_WAITING_PRECAPTURE;
            mCaptureSession.capture(mPreviewRequestBuilder.build(), mCaptureCallback,
                    mBackgroundHandler);
        } catch (CameraAccessException e) {
            e.printStackTrace();
        }
    }

    /**
     * 开始视频录制。
     */
    private void startRecordingVideo() {
        try {
            //创建录制的session会话中的请求
            CaptureRequest.Builder previewBuilder = mCameraDevice.createCaptureRequest(CameraDevice.TEMPLATE_RECORD);

            //设置录制参数，这里省略...
            SurfaceTexture texture = mTextureView.getSurfaceTexture();
            assert texture != null;

            // We configure the size of default buffer to be the size of camera preview we want.
            texture.setDefaultBufferSize(mPreviewSize.getWidth(), mPreviewSize.getHeight());

            // This is the output Surface we need to start preview.
            Surface surface = new Surface(texture);

            // Start a capture session
            // Once the session starts, we can update the UI and start recording
            mCameraDevice.createCaptureSession(Arrays.asList(surface, mImageReader.getSurface()), new CameraCaptureSession.StateCallback() {
                @Override
                public void onConfigured(@NonNull CameraCaptureSession cameraCaptureSession) {

                }

                @Override
                public void onConfigureFailed(@NonNull CameraCaptureSession cameraCaptureSession) {

                }
            }, mBackgroundHandler);
        } catch (CameraAccessException e) {
            e.printStackTrace();
        }
    }

    /**
     * Capture a still picture. This method should be called when we get a response in
     * {@link #mCaptureCallback} from both {@link #lockFocus()}.
     */
    private void captureStillPicture() {
        try {
            final Activity activity = getActivity();
            if (null == activity || null == mCameraDevice) {
                return;
            }
            // This is the CaptureRequest.Builder that we use to take a picture.
            final CaptureRequest.Builder captureBuilder =
                    mCameraDevice.createCaptureRequest(CameraDevice.TEMPLATE_STILL_CAPTURE);
            captureBuilder.addTarget(mImageReader.getSurface());

            // Use the same AE and AF modes as the preview.
            captureBuilder.set(CaptureRequest.CONTROL_AF_MODE,
                    CaptureRequest.CONTROL_AF_MODE_CONTINUOUS_PICTURE);
            setAutoFlash(captureBuilder);

            // Orientation
            int rotation = activity.getWindowManager().getDefaultDisplay().getRotation();
            captureBuilder.set(CaptureRequest.JPEG_ORIENTATION, getOrientation(rotation));

            CameraCaptureSession.CaptureCallback CaptureCallback = new CameraCaptureSession.CaptureCallback() {

                @Override
                public void onCaptureCompleted(@NonNull CameraCaptureSession session,
                                               @NonNull CaptureRequest request,
                                               @NonNull TotalCaptureResult result) {
                    showToast("Saved: " + mFile);
                    Log.d(TAG, mFile.toString());
                    unlockFocus();
                }
            };

            mCaptureSession.stopRepeating();
            mCaptureSession.abortCaptures();
            mCaptureSession.capture(captureBuilder.build(), CaptureCallback, null);
        } catch (CameraAccessException e) {
            e.printStackTrace();
        }
    }

    /**
     * Retrieves the JPEG orientation from the specified screen rotation.
     *
     * @param rotation The screen rotation.
     * @return The JPEG orientation (one of 0, 90, 270, and 360)
     */
    private int getOrientation(int rotation) {
        // Sensor orientation is 90 for most devices, or 270 for some devices (eg. Nexus 5X)
        // We have to take that into account and rotate JPEG properly.
        // For devices with orientation of 90, we simply return our mapping from ORIENTATIONS.
        // For devices with orientation of 270, we need to rotate the JPEG 180 degrees.
        return (ORIENTATIONS.get(rotation) + mSensorOrientation + 270) % 360;
    }

    /**
     * Unlock the focus. This method should be called when still image capture sequence is
     * finished.
     */
    private void unlockFocus() {
        try {
            // Reset the auto-focus trigger
            mPreviewRequestBuilder.set(CaptureRequest.CONTROL_AF_TRIGGER, CameraMetadata.CONTROL_AF_TRIGGER_CANCEL);
            setAutoFlash(mPreviewRequestBuilder);
            mCaptureSession.capture(mPreviewRequestBuilder.build(), mCaptureCallback,
                    mBackgroundHandler);
            // After this, the camera will go back to the normal state of preview.
            mState = STATE_PREVIEW;
            mCaptureSession.setRepeatingRequest(mPreviewRequest, mCaptureCallback,
                    mBackgroundHandler);
        } catch (CameraAccessException e) {
            e.printStackTrace();
        }
    }

    @Override
    public void onClick(View view) {
        switch (view.getId()) {
            case R.id.picture: {
                takePicture();
                break;
            }
            case R.id.info: {
                Activity activity = getActivity();
                if (null != activity) {
                    new AlertDialog.Builder(activity)
                            .setMessage("intro_message")
                            .setPositiveButton(android.R.string.ok, null)
                            .show();
                }
                break;
            }
            case R.id.switch_camera:
                switchCamera();
                break;
        }
    }

    /**
     * 切换摄像头
     */
    private void switchCamera() {
        if (mChangedCameraId == null) {
            mChangedCameraId = mCameraId;
        }
        if (TextUtils.equals(mChangedCameraId, String.valueOf(CameraCharacteristics.LENS_FACING_FRONT))) {
            mChangedCameraId = String.valueOf(CameraCharacteristics.LENS_FACING_BACK);
        } else {
            mChangedCameraId = String.valueOf(CameraCharacteristics.LENS_FACING_FRONT);
        }
        //先关闭，再开启相机
        closeCamera();
        if (mTextureView.isAvailable()) {
            openCamera(mTextureView.getWidth(), mTextureView.getHeight());
        } else {
            mTextureView.setSurfaceTextureListener(mSurfaceTextureListener);
        }

        Log.i(TAG, "switchCamera: " + mChangedCameraId);
    }

    private void setAutoFlash(CaptureRequest.Builder requestBuilder) {
        if (mFlashSupported) {
            requestBuilder.set(CaptureRequest.CONTROL_AE_MODE,
                    CaptureRequest.CONTROL_AE_MODE_ON_AUTO_FLASH);
        }
    }

    /**
     * Saves a JPEG {@link Image} into the specified {@link File}.
     */
    private static class ImageSaver implements Runnable {

        /**
         * The JPEG image
         */
        private final Image mImage;
        /**
         * The file we save the image into.
         */
        private final File mFile;

        ImageSaver(Image image, File file) {
            mImage = image;
            mFile = file;
        }

        @Override
        public void run() {
            ByteBuffer buffer = mImage.getPlanes()[0].getBuffer();
            byte[] bytes = new byte[buffer.remaining()];
            buffer.get(bytes);
            FileOutputStream output = null;
            try {
                output = new FileOutputStream(mFile);
                output.write(bytes);
            } catch (IOException e) {
                e.printStackTrace();
            } finally {
                mImage.close();
                if (null != output) {
                    try {
                        output.close();
                    } catch (IOException e) {
                        e.printStackTrace();
                    }
                }
            }
        }

    }

    /**
     * Compares two {@code Size}s based on their areas.
     */
    static class CompareSizesByArea implements Comparator<Size> {

        @Override
        public int compare(Size lhs, Size rhs) {
            // We cast here to ensure the multiplications won't overflow
            return Long.signum((long) lhs.getWidth() * lhs.getHeight() -
                    (long) rhs.getWidth() * rhs.getHeight());
        }

    }

    /**
     * Shows an error message dialog.
     */
    public static class ErrorDialog extends DialogFragment {

        private static final String ARG_MESSAGE = "message";

        public static ErrorDialog newInstance(String message) {
            ErrorDialog dialog = new ErrorDialog();
            Bundle args = new Bundle();
            args.putString(ARG_MESSAGE, message);
            dialog.setArguments(args);
            return dialog;
        }

        @NonNull
        @Override
        public Dialog onCreateDialog(Bundle savedInstanceState) {
            final Activity activity = getActivity();
            return new AlertDialog.Builder(activity)
                    .setMessage(getArguments().getString(ARG_MESSAGE))
                    .setPositiveButton(android.R.string.ok, new DialogInterface.OnClickListener() {
                        @Override
                        public void onClick(DialogInterface dialogInterface, int i) {
                            activity.finish();
                        }
                    })
                    .create();
        }

    }

    /**
     * Shows OK/Cancel confirmation dialog about camera permission.
     */
    public static class ConfirmationDialog extends DialogFragment {

        @NonNull
        @Override
        public Dialog onCreateDialog(Bundle savedInstanceState) {
            final Fragment parent = getParentFragment();
            return new AlertDialog.Builder(getActivity())
                    .setMessage(R.string.request_permission)
                    .setPositiveButton(android.R.string.ok, new DialogInterface.OnClickListener() {
                        @Override
                        public void onClick(DialogInterface dialog, int which) {
                            parent.requestPermissions(new String[]{Manifest.permission.CAMERA},
                                    REQUEST_CAMERA_PERMISSION);
                        }
                    })
                    .setNegativeButton(android.R.string.cancel,
                            new DialogInterface.OnClickListener() {
                                @Override
                                public void onClick(DialogInterface dialog, int which) {
                                    Activity activity = parent.getActivity();
                                    if (activity != null) {
                                        activity.finish();
                                    }
                                }
                            })
                    .create();
        }
    }

    private void getMatchingSize2() {
        try {
            CameraManager mCameraManager = (CameraManager) getActivity().getSystemService(Context.CAMERA_SERVICE);
            for (final String cameraId : mCameraManager.getCameraIdList()) {
                CameraCharacteristics cameraCharacteristics = mCameraManager.getCameraCharacteristics(cameraId);
                StreamConfigurationMap streamConfigurationMap = cameraCharacteristics.get(CameraCharacteristics.SCALER_STREAM_CONFIGURATION_MAP);
                Size[] sizes = streamConfigurationMap.getOutputSizes(ImageFormat.JPEG);
                for (int i = 0; i < sizes.length; i++) {
                    Log.e(TAG, "支持的分辨率：" + sizes[i].getWidth() + "*" + sizes[i].getHeight());
                }
            }
            DisplayMetrics displayMetrics = getResources().getDisplayMetrics(); //因为我这里是将预览铺满屏幕,所以直接获取屏幕分辨率
            int deviceWidth = displayMetrics.widthPixels; //屏幕分辨率宽
            int deviceHeigh = displayMetrics.heightPixels; //屏幕分辨率高
            Log.e(TAG, "getMatchingSize2: 屏幕密度宽度=" + deviceWidth);
            Log.e(TAG, "getMatchingSize2: 屏幕密度高度=" + deviceHeigh);

        } catch (CameraAccessException e) {
            e.printStackTrace();
        }

    }
}


/**
 * CameraCharacteristics:
 * 是一个包含相机参数的对象，可以通过一些key获取对应的values.
 * <p>
 * ----------------------------------------------------------------
 * LENS_FACING:获取摄像头方向。LENS_FACING_FRONT是前摄像头，LENS_FACING_BACK是后摄像头。
 * <p>
 * SENSOR_ORIENTATION：获取摄像头拍照的方向。
 * <p>
 * FLASH_INFO_AVAILABLE：获取是否支持闪光灯。
 * <p>
 * SCALER_AVAILABLE_MAX_DIGITAL_ZOOM：获取最大的数字调焦值，也就是zoom最大值。
 * <p>
 * LENS_INFO_MINIMUM_FOCUS_DISTANCE：获取最小的调焦距离，某些手机上获取到的该values为null或者0.0。前摄像头大部分有固定焦距，无法调节。
 * <p>
 * INFO_SUPPORTED_HARDWARE_LEVEL：获取摄像头支持某些特性的程度。
 * <p>
 * 以下手机中支持的若干种程度：
 * <p>
 * INFO_SUPPORTED_HARDWARE_LEVEL_FULL：全方位的硬件支持，允许手动控制全高清的摄像、支持连拍模式以及其他新特性。
 * <p>
 * INFO_SUPPORTED_HARDWARE_LEVEL_LIMITED：有限支持，这个需要单独查询。
 * <p>
 * INFO_SUPPORTED_HARDWARE_LEVEL_LEGACY：所有设备都会支持，也就是和过时的Camera API支持的特性是一致的。
 * ————————————————
 * <p>
 * CameraDevice:
 * CameraDevice的reateCaptureRequest(int templateType)方法创建CaptureRequest.Builder。
 * ---------------------------------------------------
 * templateType参数有以下几种：
 * <p>
 * TEMPLATE_PREVIEW ：预览
 * <p>
 * TEMPLATE_RECORD：拍摄视频
 * <p>
 * TEMPLATE_STILL_CAPTURE：拍照
 * <p>
 * TEMPLATE_VIDEO_SNAPSHOT：创建视视频录制时截屏的请求
 * <p>
 * TEMPLATE_ZERO_SHUTTER_LAG：创建一个适用于零快门延迟的请求。在不影响预览帧率的情况下最大化图像质量。
 * <p>
 * TEMPLATE_MANUAL：创建一个基本捕获请求，这种请求中所有的自动控制都是禁用的(自动曝光，自动白平衡、自动焦点)。
 * ————————————————
 * <p>
 * CameraDevice:
 * CameraDevice的reateCaptureRequest(int templateType)方法创建CaptureRequest.Builder。
 * ---------------------------------------------------
 * templateType参数有以下几种：
 * <p>
 * TEMPLATE_PREVIEW ：预览
 * <p>
 * TEMPLATE_RECORD：拍摄视频
 * <p>
 * TEMPLATE_STILL_CAPTURE：拍照
 * <p>
 * TEMPLATE_VIDEO_SNAPSHOT：创建视视频录制时截屏的请求
 * <p>
 * TEMPLATE_ZERO_SHUTTER_LAG：创建一个适用于零快门延迟的请求。在不影响预览帧率的情况下最大化图像质量。
 * <p>
 * TEMPLATE_MANUAL：创建一个基本捕获请求，这种请求中所有的自动控制都是禁用的(自动曝光，自动白平衡、自动焦点)。
 * ————————————————
 * <p>
 * CameraDevice:
 * CameraDevice的reateCaptureRequest(int templateType)方法创建CaptureRequest.Builder。
 * ---------------------------------------------------
 * templateType参数有以下几种：
 * <p>
 * TEMPLATE_PREVIEW ：预览
 * <p>
 * TEMPLATE_RECORD：拍摄视频
 * <p>
 * TEMPLATE_STILL_CAPTURE：拍照
 * <p>
 * TEMPLATE_VIDEO_SNAPSHOT：创建视视频录制时截屏的请求
 * <p>
 * TEMPLATE_ZERO_SHUTTER_LAG：创建一个适用于零快门延迟的请求。在不影响预览帧率的情况下最大化图像质量。
 * <p>
 * TEMPLATE_MANUAL：创建一个基本捕获请求，这种请求中所有的自动控制都是禁用的(自动曝光，自动白平衡、自动焦点)。
 * ————————————————
 * <p>
 * CameraDevice:
 * CameraDevice的reateCaptureRequest(int templateType)方法创建CaptureRequest.Builder。
 * ---------------------------------------------------
 * templateType参数有以下几种：
 * <p>
 * TEMPLATE_PREVIEW ：预览
 * <p>
 * TEMPLATE_RECORD：拍摄视频
 * <p>
 * TEMPLATE_STILL_CAPTURE：拍照
 * <p>
 * TEMPLATE_VIDEO_SNAPSHOT：创建视视频录制时截屏的请求
 * <p>
 * TEMPLATE_ZERO_SHUTTER_LAG：创建一个适用于零快门延迟的请求。在不影响预览帧率的情况下最大化图像质量。
 * <p>
 * TEMPLATE_MANUAL：创建一个基本捕获请求，这种请求中所有的自动控制都是禁用的(自动曝光，自动白平衡、自动焦点)。
 * ————————————————
 * <p>
 * CameraDevice:
 * CameraDevice的reateCaptureRequest(int templateType)方法创建CaptureRequest.Builder。
 * ---------------------------------------------------
 * templateType参数有以下几种：
 * <p>
 * TEMPLATE_PREVIEW ：预览
 * <p>
 * TEMPLATE_RECORD：拍摄视频
 * <p>
 * TEMPLATE_STILL_CAPTURE：拍照
 * <p>
 * TEMPLATE_VIDEO_SNAPSHOT：创建视视频录制时截屏的请求
 * <p>
 * TEMPLATE_ZERO_SHUTTER_LAG：创建一个适用于零快门延迟的请求。在不影响预览帧率的情况下最大化图像质量。
 * <p>
 * TEMPLATE_MANUAL：创建一个基本捕获请求，这种请求中所有的自动控制都是禁用的(自动曝光，自动白平衡、自动焦点)。
 * ————————————————
 * <p>
 * CameraDevice:
 * CameraDevice的reateCaptureRequest(int templateType)方法创建CaptureRequest.Builder。
 * ---------------------------------------------------
 * templateType参数有以下几种：
 * <p>
 * TEMPLATE_PREVIEW ：预览
 * <p>
 * TEMPLATE_RECORD：拍摄视频
 * <p>
 * TEMPLATE_STILL_CAPTURE：拍照
 * <p>
 * TEMPLATE_VIDEO_SNAPSHOT：创建视视频录制时截屏的请求
 * <p>
 * TEMPLATE_ZERO_SHUTTER_LAG：创建一个适用于零快门延迟的请求。在不影响预览帧率的情况下最大化图像质量。
 * <p>
 * TEMPLATE_MANUAL：创建一个基本捕获请求，这种请求中所有的自动控制都是禁用的(自动曝光，自动白平衡、自动焦点)。
 * ————————————————
 * <p>
 * CameraDevice:
 * CameraDevice的reateCaptureRequest(int templateType)方法创建CaptureRequest.Builder。
 * ---------------------------------------------------
 * templateType参数有以下几种：
 * <p>
 * TEMPLATE_PREVIEW ：预览
 * <p>
 * TEMPLATE_RECORD：拍摄视频
 * <p>
 * TEMPLATE_STILL_CAPTURE：拍照
 * <p>
 * TEMPLATE_VIDEO_SNAPSHOT：创建视视频录制时截屏的请求
 * <p>
 * TEMPLATE_ZERO_SHUTTER_LAG：创建一个适用于零快门延迟的请求。在不影响预览帧率的情况下最大化图像质量。
 * <p>
 * TEMPLATE_MANUAL：创建一个基本捕获请求，这种请求中所有的自动控制都是禁用的(自动曝光，自动白平衡、自动焦点)。
 * ————————————————
 * <p>
 * CameraDevice:
 * CameraDevice的reateCaptureRequest(int templateType)方法创建CaptureRequest.Builder。
 * ---------------------------------------------------
 * templateType参数有以下几种：
 * <p>
 * TEMPLATE_PREVIEW ：预览
 * <p>
 * TEMPLATE_RECORD：拍摄视频
 * <p>
 * TEMPLATE_STILL_CAPTURE：拍照
 * <p>
 * TEMPLATE_VIDEO_SNAPSHOT：创建视视频录制时截屏的请求
 * <p>
 * TEMPLATE_ZERO_SHUTTER_LAG：创建一个适用于零快门延迟的请求。在不影响预览帧率的情况下最大化图像质量。
 * <p>
 * TEMPLATE_MANUAL：创建一个基本捕获请求，这种请求中所有的自动控制都是禁用的(自动曝光，自动白平衡、自动焦点)。
 * ————————————————
 */

/**
 * CameraDevice:
 * CameraDevice的reateCaptureRequest(int templateType)方法创建CaptureRequest.Builder。
 * ---------------------------------------------------
 * templateType参数有以下几种：
 *
 * TEMPLATE_PREVIEW ：预览
 *
 * TEMPLATE_RECORD：拍摄视频
 *
 * TEMPLATE_STILL_CAPTURE：拍照
 *
 * TEMPLATE_VIDEO_SNAPSHOT：创建视视频录制时截屏的请求
 *
 * TEMPLATE_ZERO_SHUTTER_LAG：创建一个适用于零快门延迟的请求。在不影响预览帧率的情况下最大化图像质量。
 *
 * TEMPLATE_MANUAL：创建一个基本捕获请求，这种请求中所有的自动控制都是禁用的(自动曝光，自动白平衡、自动焦点)。
 * ————————————————
 */
